Effect of Substituting Fishmeal with Oilseed Meals on Diets Fatty AcidandProximate Composition for Nile tilapia (Oreochromis niloticus)

Abstract

The study aimed to evaluate the fatty acid and proximate composition of diets for Nile tilapia containing soybean meal (SBM), canola meal (CM) and sunflower meal (SFM) as replacements of fishmeal (FM). A control diet (D1) of 30% crude protein (CP) was formulated using fishmeal as main protein source. The test diets (D2, D3 and D4) were formulated by replacing 10% CP of FM by SBM, CM and SFM, respectively. The fatty acid profile of ingredients and diets were determined by MPA FT-NIR spectrometer. FM displayed higher CP content (62.60%) followed by SBM (47.38%), CM (34.39%) and SFM (24.81%). SFM had highest crude fibre content (p<0.05) while CM displayed higher figure for ether extracts (p<0.05). Substituting FM with SBM, CM and SFM increased the levels of crude fibre (p<0.05). Diet 4 recorded highest crude fibre (16.03%) content (p<0.05), while CM based diet recorded highest ether extract content (10.75%), (p<0.05). Diet 1 had lowest concentration (21.85mg/100g) of total saturated fatty acid and D2 lowest concentration of polyunsaturated fatty acid (29.90mg/100g). The study revealed that 10% CP substitution of FM with SBM, CM and SFM in Nile tilapia diets is possible without much negative change in diets proximate and fatty acid composition. Key words: Crude protein, Essential fatty acids, Nile tilapia, Nutrients composition